Wind Energy Setup and Maintenance

This page is the do-it-yourself wind energy research, cost analysis, implementation, and maintenance open source hub for the Highest Good energy component of One Community. It discusses our wind energy infrastructure details with the following sections:

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WHAT IS WIND ENERGY

Wind Energy is the energy carried by the winds, caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth’s surface, and rotation of the Earth. Wind-flow patterns are modified by the Earth’s terrain, bodies of water, and vegetative cover. This wind flow (motion energy) when “harvested” by modern wind turbines can be used to generate electricity. This electricity is a renewable source because, as long as there is sun, there will also be wind.

So how is power generated? In simple terms, the energy in the wind rotates the blades of a windmill or tower structure, these blades then rotate the shaft of a turbine encased inside the structure. This turbine then functions as a generator which produces electricity as its shafts turn. This electricity is then given to a customer (residential), a group of customers (community), or is collected along with other windmills (wind farms) to supply to a large-scale transmission grid.

The process looks like this:

Here’s a video about how a wind turbine works:

Here is a visual representation of the process of wind energy being used to provide power to a building:

WHY OPEN SOURCE
WIND ENERGY DESIGN AND SETUP

Sustainable and open-source-replicable energy infrastructure is part of One Community’s goals for helping create self-replicating and sustainable teacher/demonstration hubs collaborating for positive global change. What we see as missing, for those with a cleaner and more sustainable vision of electric power, is helpful guidance and do-it-yourself tutorials. Millions of people around the globe still lack reliable electricity and governments are still years away from connecting all these places with their respective state grids. We’re open sourcing wind energy design and setup to show how people can create electricity for themselves.

With the advent of the different types of renewable energy sources like wind, solar, biogas, etc. and their constantly decreasing prices, the ability for people to create their own renewable power source is better than ever before. Add appropriate technical know-how of renewable energy systems and installation can be fairly easy.

This has the potential to help:

People desiring a more sustainable way of living

People in places power isn’t currently available

People desiring more power self-sufficiency and security

Additionally, in places where there isn’t enough year-round sun, wind can be the best renewable energy option available. With this open source wind energy system tutorial, we hope to provide a replicable and easy-to-follow path to assessing, designing, installing, operating, and maintaining your own wind energy system. The easier, more affordable, and more attractive wind energy can be demonstrated, the more people will adopt it.

WAYS TO CONTRIBUTE TO EVOLVING THIS SUSTAINABILITY COMPONENT WITH US

CONSULTANTS ON THIS COMPONENT OF ONE COMMUNITY

WIND ENERGY
DESIGN & IMPLEMENTATION DETAILS

Whether you are considering a grid-tied or stand-alone wind energy system, there are 4 main components that need to be considered: Assessment, Design, Installation, and Maintenance. We will use our case of a small wind energy system and explore the details of these 4 components with the following sections:

GRID-TIED VS. STANDALONE WIND SYSTEMS OVERVIEW

This adoption of a wind energy system can come in the form of a grid-tied system or a standalone system. Both have their advantages and disadvantages. Here’s a quick overview of both. Details of all components are discussed more in the sections that follow.

GRID-TIED WIND SYSTEM EXAMPLE

In the grid-tied system example below you see energy (AC) produced by wind is sent to a controller to distribute some power to the residential area nearby and then the rest of the power is sent to the grid via a grid-tied inverter. The grid-tied inverter ensures that the quality of the power and frequency are maintained and the wind system remains isolated from faults on the grid. Nowadays companies like Schneider Electric, ABB, etc. sell advanced grid-tied inverters which play the role of controller as well, thus saving on equipment and space needs.

STAND-ALONE WIND SYSTEM EXAMPLE

In a stand-alone system like the one shown below, there isn’t a need to have a grid-tied inverter or utility connection. This decreases the overall cost of connections but at the sacrifice of security and reliability because of the absence of a connection to the (usually much more resilient) electric grid.

Understanding these differences though is only the first step. Before choosing a system, you must identify if wind energy is a good choice and allowed for your specific location. Read on for details about how to determine this.

ASSESSMENT & SURVEYING

Before deciding on wind as an energy source you’ll be using, you need to check if you are allowed to install a wind turbine or not, if there is enough wind for a system like this, and then the best place to construct it. In the United States, some counties may not allow you to have a wind turbine or they may allow them but only with a special license. Before you invest in a wind energy system, research potential zoning and neighborhood rules and/or regulations. You can do this by contacting the county/local building inspector, board of supervisors, and/or planning board. They will tell you if you will need to obtain a building permit and provide you with a list of requirements.

After that, you need to see if your area receives enough wind and with enough speed. Wind speed increases with increase in height. Generally for a small wind energy system the height is 20-30 m. So you will need the wind speed at that particular height. For that, you can use different wind-resource maps like these:

If you live out of the U.S., there should be a different database specifically for your country. If there isn’t one, you can check meteorological websites or offices for your own country which might have some data. Otherwise, contact your nearest airport to get the estimated wind speed in your area and/or get a wind speed measurement from a professional.

If your area has a relatively constant wind speed of 5 m/s (about 10 mph) or more, then small wind turbines might be a good fit for you. The reason for this is that the typical minimum speed at which the wind turbine starts to produce power is 3.5-4 m/s, which is called the cut-in speed of a turbine. At 10-12 m/s they produce the maximum power, when there is a storm and winds reach extremely high speed (>=25m/s), the wind turbines are designed in such a way that they stop operating (by braking), this speed is called the cut out speed which ensures there is no damage to the turbine.

One more thing you might want to survey for before you jump to designing the wind energy system is the best location for the wind tower. The rule of thumb for choosing your wind tower location is

No considerable hindrance in a 250-300 foot radius of the turbine

The turbine should be mounted at least 25-30 feet above any nearby wind obstructions

Here is a picture illustrating placement with consideration of obstructions:

These height needs and desire for clearance around your wind turbine may make rooftop installation a choice worth exploring. If you do this, take into consideration the strength of your building and if local codes permit it. Once you believe that your location is qualified as per the assessment, you can then proceed to the design of your system.

EVALUATION AND SELECTION OF EQUIPMENT

Evaluation and selection of equipment will start with designing your electrical system and consideration of the complete installation process. To identify what you can do on your own and where you may wish to seek help, ask yourself the following questions:

Can I pour a proper cement foundation and install guy wires?

Do I have access to a lift or other way of erecting the tower safely?

Do I know the difference between alternating current (AC) and direct current (DC) wiring?

Do I know enough about electricity to safely wire my turbine?

Do I know how to safely handle and install batteries?

Do I know how controllers, inverters, disconnect switches and voltage stabilizers work?

If you answered yes to all of these, you can likely make a completely independent wind energy system on your own. For any areas you don’t feel comfortable or knowledgeable enough to do on your own, call a professional or conduct more research. Building a small “test model” can also be helpful.

Here’s an image showing what you should expect for your equipment:

Schematic of a sample small grid connected wind energy system

STANDALONE VS. OFF-GRID SYSTEM EQUIPMENT CONSIDERATIONS

Next you need to decide what kind of wind system you want to build. There are two types: Standalone (or Off-grid) and Grid-connected. Standalone, as the name suggests, is a completely off-grid system where it is supported by batteries to maintain the energy supply when wind isn’t sufficient. Grid-connected is where the electricity supplied by the wind is supported by the main grid to fill any voids created by the intermittency of wind. A disconnect switch is used in this case instead of the batteries.

Grid-connected systems can be practical if the following conditions exist:

You live in an area with average annual wind speed of at least 10 miles per hour (4.5 m/s)

Utility-supplied electricity is expensive in your area (above 10–15 cents per kilowatt-hour)

The utility’s requirements for connecting your system to its grid are not prohibitively expensive

There are good incentives for the sale of excess electricity or for the purchase of wind turbines

Standalone systems make more sense when:

You live in an area with average annual wind speed of at least 9 miles per hour (4.0 meters per second)

A grid connection is not available or can only be made through an expensive extension. The cost of running a power line to a remote site to connect with the utility grid can be prohibitive, ranging from $15,000 to more than $50,000 per mile, depending on terrain

You would like to gain energy independence from the utility

In the end, if all the legal requirements are met, the major decision maker is usually economic considerations. E.g: Batteries might have a high initial cost but getting the grid connected to your remote location might be even costlier. So there needs to be a careful evaluation. The sections that follow are purposed to help.

EVALUATING ENERGY NEEDS

Evaluating energy needs is one of the first steps for system design. For any wind energy system, be it off-grid or grid-connected, we have some components in common: A wind turbine, a tower, a concrete foundation for the tower, and cable connections from the turbine to the equipment room. The sizing and selection of this equipment though will vary based on your energy needs.

For example, choosing a wind turbine we need two things:

Size required

Wind speed available at height where it is to be mounted (determined during the the Assessment and Surveying section above and needed to decide the cut-in speed)

Using energy projections for your specific situation, you can then decide on what size turbine is best for you. The average yearly energy consumption of a normal household (4 members) in the US is around 12000 kWh, which is almost the highest in the world. It is way less for other countries like India, where it is around 900 kWh. So it changes from place to place. For reference, see this 2010 data chart:

You need to assess your specific energy needs. For calculating your energy needs, you can either do it manually or get an energy auditor. If you want to make your own estimate, there are many free online resources available to help you like this one: http://www.cpi.coop/my-account/online-usage-calculator.

EVALUATING YOUR CAPACITY FACTOR

Next, evaluate your capacity factor. The capacity factor is the average power generated, divided by the rated peak power. This varies by location and is needed to be sure you size your turbine large enough to meet your needs.

Using an example of a wind turbine with a five-megawatt peak power rating: If it produces power in your location at an average of two megawatts, then its capacity factor is 40% (2 mW average ÷ 5 mW peak = 0.40, i.e. 40%). Since wind is an intermittent source of energy, it cannot power the turbine at optimum level all the time, so the design being able to sufficiently meet your needs is contingent upon this capacity factor.

Generally, effective wind energy systems should lie in the range of a 25-45% capacity factor. Wind farms are designed for maximum efficiency and can have a capacity factor as high as 55%. For reference, a 1.5-kilowatt wind turbine with a capacity factor of 30% will meet the needs of a home requiring 300 kilowatt-hours per month in a location with a 14 mile-per-hour (6.26 meters-per-second) annual average wind speed.

How are these calculations made? Suppose the monthly energy requirement of a household is 1000 kWh and we know number of hours in a month is 720. So hourly power required is 1000/720 = 1.4 kW (1.388 rounded up). If we assume a 30% capacity factor, then the required size of the turbine would be (1.4/0.3=4.667) 4.67 kW or 5 kW when rounded up.

If you are willing to work from scratch and/or want to save money, you can make your own wind turbine as well. There are some interesting videos on instructables, wikihow, as well as Youtube. See our resources section for some examples.

If you are considering making your own wind turbine, or want to get to get a preliminary estimate of the performance you can expect from any equipment that doesn’t list it, you can use the following formula:

AEO= 0.01328 D2 V3

Where:

AEO = Annual energy output (kilowatt-hours/year)

D = Rotor diameter, feet

V = Annual average wind speed, miles-per hour (mph), at your site

PURCHASING AND ACQUISITION

When you buy turbines and blades from dealers, most of them offer either complete turnkey (ready-to-operate) installations or the option for customers to purchase directly from the factory and install the system themselves. The first option offers more customer support from the company. Self-installation offers significant savings and a hands-on understanding of the turbine. Prospective owners can discuss the options available with manufacturers to decide which method best suits their budget and technical skills.

Approach buying the equipment as you would any major purchase. You will need to weigh costs and various degrees of design ruggedness/durability. Obtain and review the product literature from several manufacturers, and research those you want to pursue to ensure they are recognized businesses and their parts and service will be available when you need them. Find out how long the warranty lasts and what it includes, and ask for references of customers with installations similar to the one you are considering. Ask system owners about performance, reliability, maintenance and repair requirements, and whether the system is meeting their expectations. We’ll additionally be providing all these details here on this page once we have our own experience to share.

Dealers should also provide you with the logistics of the turbine and blades delivery, but if they don’t, or if by not using their delivery service gets you a big discount, then you will need a big truck or you will need to have a tow trailer to get the turbine from the dealer to your home. Be very careful with the machine and only go with a self-delivery option if you have previous experience with moving heavy stuff. Remember, safety is primary and money secondary.

Once we’ve completed our own purchasing process and completed installation, we’ll make and add a more details video tutorial here.

VIDEO COMING OF: PURCHASING A WIND TURBINE SYSTEM – THIS TUTORIAL WILL SHARE WHAT WE LEARNED FROM OUR OWN WIND TURBINE PURCHASING-RESEARCH AND DELIVERY PROCESS

PLACEMENT AND TOWER-TYPE CONSIDERATIONS

Intelligent placement of your wind turbine is important to maximizing its function. On a plateau/mesa, winds may be very turbulent running off a cliff causing wind shears. It is important to site the generator far enough from the cliff to avoid turbulent wind.

On ridge tops, wind compresses as it blows over the top of a hill, increasing the wind speed. With proper placement, you may be able to use a shorter tower. The general recommendation though is no tower shorter than 33 feet (10 m). It is also important to follow the general rule that the tower be at least 20 feet (6 m) above any surrounding object.

Coastal or lakeside usually offers very strong prevailing winds. In the case of coastal, winds typically blow most from the ocean, so it is very beneficial to install your wind generator as close to the coastline as possible. Trees and taller structures can be downwind from the wind generator.

Wherever placed, a wind turbine must also have a clear path for the wind and machinery to perform efficiently. Turbulence reduce performance and “work” the turbine harder than smooth air. Turbulences are stronger close to the ground, diminish with height, and are generally created by obstacles. Wind speed also increases with height. The general rule, as previously stated, you should install a wind turbine on a tower such that it is at least 20 ft above any obstacles within 250 ft. Keep in mind though that large obstacles will affect wind patterns even if they are farther than 250 feet away.

Smaller turbines typically go on shorter towers than larger turbines. A 1 kW turbine is often, for example, installed on a 30-50 ft tower, while a 10 kW turbine will usually need a tower of 60-100 ft. Careful analysis and consideration are recommended if considering mounting wind turbines to small buildings that people live in because of the inherent problems of turbulence, noise, and vibration.

When choosing your location, keep in mind the process of erecting your tower too. The three basic tower types to consider are tilt-ups, guyed lattice, and freestanding. Most tilt-ups are made of pipe or tube and require guy wires for support. They are assembled on the ground and raised into position with a winch or tow vehicle. For turbines with a rotor diameter of 12 feet or less, this tower is usually the lowest-cost option. Guyed lattice towers are constructed on the ground and raised with a crane or assembled vertically, one section at a time, with a process known as stacking. These towers are mostly used for turbines with rotor diameters less than 25 feet and are the lowest cost fixed-tower option. Freestanding towers fall into two categories: self-supporting lattice and monopole. The self-supporting lattice tower is usually assembled on the ground and raised with a crane. These towers are typically used for turbines with a rotor diameter of 20 feet or more and require a fairly large foundation, making this option fairly expensive. Monopole towers are available for most turbine sizes and tilt-up versions are becoming more common. Although many people prefer the aesthetics of a monopole, these towers require the largest foundation of all and are usually the most expensive option.

Towers, particularly guyed towers, can be hinged at their base and suitably equipped to allow them to be tilted up or down using a winch or vehicle. This allows all work to be done at ground level. Some towers and turbines can be easily erected by the purchaser, while others are best left to trained professionals. Anti-fall devices, consisting of a wire with a latching runner, are available and are highly recommended for any tower that will be climbed.

Aluminum towers should be avoided because they are prone to developing cracks. Towers are usually offered by wind turbine manufacturers and purchasing one from them is the best way to ensure proper compatibility.

Again, mounting wind turbines on top of homes is something to be cautions about. Larger residential-home wind turbines vibrate and transmit noise to the structure on which they are mounted. This vibration can lead to noise and structural problems with the building. Mounting on the rooftop can also expose the generator to excessive turbulence that shortens its life.

Once we’ve chosen and installed our own tower, we’ll make and include here a video series on tower selection and installation.

VIDEO COMING OF: WIND TOWER SELECTION & INSTALLATION – THIS TUTORIAL WILL BE A SHORT OVERVIEW OF WHY WE ENDED UP CHOOSING OUR SPECIFIC TOWER AND INSTALLATION APPROACH

NOISE ISSUES

Small wind turbines do make some noise, but not enough to be found objectionable by most people. A typical residential wind system makes less noise than the average washing machine. This is because most residential-sized wind generators are direct-drive devices with few moving parts. Unlike the utility-scale turbines used in wind farms, they do not have high-speed transmissions. Thus, most of the sound that comes from a residential sized wind turbine is aerodynamic noise caused by the blades passing through the air. So the noise level of most modern residential turbines measures close to the ambient noise levels under average wind conditions. It is audible, if you are out of doors and listening for it, but no noisier than your average refrigerator.

As a side note, small wind turbines do not interfere with TV reception. In very general terms, homes within a few kilometers of a large wind development that have TV aerials pointed towards the turbines are likely to be at the highest risk. There is a common misconception that digital TV is immune to interference from wind turbines, this is unfortunately not true. In general though, turbines with small diameters are unlikely to have effects on television and radio reception. If this occurs it is likely to be highly localized and technically easy to overcome.

UNDERSTANDING WIND-SYSTEM COMPONENTS

To get you started down the right road in understanding and using wind energy, this section outlines the basic system components and an explanation where appropriate of these component differences for grid-tied and off-grid systems. Our hope is that you’ll be able to make better decisions and choices by understanding the system and components better.

Wind Generator

Tower

Brake

Controller

Dump Load

Battery Bank

System Meter

Main DC Disconnect

Inverter

AC Breaker Panel

Backup Generator

Plus wiring, grounding, and other miscellaneous small parts…

Wind Generator (aka: Wind Genny or Wind Turbine): The wind generator is what actually generates electricity in the system. Most modern wind generators are upwind designs (blades are on the side of the tower that faces into the wind), and couple permanent magnet alternators directly to the rotor (blades). Three-bladed wind generators are most common, providing a good compromise between efficiency and rotor balance.

Small wind turbines protect themselves from high winds (governing) by tilting the rotor up or to the side, or by changing the pitch of the blades. Electricity is transmitted down the tower on wires, most often as three-phase wild alternating current (AC).

It’s called “wild” because the voltage and frequency vary with the rotational speed of the wind turbine. The output is then rectified to direct current (DC) to charge batteries or to be inverted for grid connection.

A small 2.5 kW wind turbine

Tower: The wind generator tower is very often more expensive than the turbine. The tower puts the turbine up in the “fuel”—the smooth and strong winds that give the most energy. In support of this and as stated earlier, wind turbines should be sited at least 30 feet (9 m) higher than anything within 250 feet; double this or even more if the object is a major land feature.

The three common types of towers are tilt-up, fixed-guyed, and freestanding. Towers must be specifically engineered for the lateral thrust and weight of the turbine, and should be adequately grounded to protect your equipment against lightning damage.

Brake (aka: Emergency Shutdown Mechanism): Most wind turbines have some means of stopping the turbine for repairs, in an emergency, for routine maintenance, or when the energy is not needed. Many turbines have “dynamic braking,” which simply shorts out the three electrical phases and acts as a disconnect. Others have mechanical braking, either via a disc or drum brake, activated by a small winch at the base of the tower. Still others have mechanical furling, which swings the rotor out of the wind. Mechanical braking is usually more effective and reliable than dynamic braking.

A charge controller

Charge Controller (aka: Controller or Regulator): A wind-electric charge controller’s primary function is to protect your battery bank from overcharging. It does this by monitoring the battery bank—when the bank is fully charged, the controller sends energy from the battery bank to a dump (diversion) load.

Many wind-electric charge controllers are built into the same box as the rectifiers (AC-to-DC converters). Overcurrent protection is needed between the battery and controller/dump load.

In batteryless grid-tie systems, there is no controller in normal operation, since the inverter is selling whatever energy the turbine is generating. But there will be some control function in the case of grid failure, and there may be electronics before the inverter to regulate the input voltage.

A dump load controller looks something like this bbb

Dump Load (aka: Diversion Load or Shunt Load): Solar-electric modules can be turned off—open circuited—with no damage. Most wind generators should not run unloaded. They will run too fast and too loud, and may self-destruct. They must be connected to a battery bank or load. So normally, a charge controller that has the capability of being a diversion controller is used. A diversion controller takes surplus energy from the battery bank and sends it to a dump load. In contrast, a series controller (commonly used in PV systems), actually opens the circuit.

A dump load is an electrical resistance heater, and it must be sized to handle the full generating capacity of the wind generator used. These dump loads can be air or water heaters, and are activated by the charge controller whenever the batteries or the grid cannot accept the energy being produced.

Duracell deep cycle batteries

Battery Bank (aka: Storage Batteries): Your wind generator will produce electricity whenever the wind blows above the cut-in speed. If your system is off-grid, you’ll need a battery bank, a group of batteries wired together to store energy so you can have electricity when it’s not windy. For off-grid systems, battery banks are typically sized to keep household electricity running for one to three calm days. Grid-intertied systems also can include battery banks to provide emergency backup during blackouts. These will usually be smaller than off-grid battery banks because they are purposed only for keeping critical electric loads operating until the grid is up again.

Use only deep-cycle batteries (batteries designed to be regularly deeply discharged using most of its capacity) in wind-electric systems. Lead-acid batteries are the most common battery of this type. Flooded lead-acid batteries are usually the least expensive, but require adding distilled water occasionally to replenish water lost during the normal charging process. Sealed absorbed glass mat (AGM) batteries are maintenance free and designed for grid-tied systems where the batteries are typically kept at a full state of charge. Sealed gel-cell batteries can be a good choice to use in unheated spaces due to their freeze-resistant qualities.

System Meter (aka: Battery Monitor, Amp-hour Meter, Watt-hour Meter, KWH Meter, or Utility Meter): System meters can measure and display several different aspects of your wind-electric system’s performance and status – tracking how full your battery bank is, how much electricity your wind generator is producing or has produced, and how much electricity is in use. Operating your system without metering is like running your car without any gauges. Although possible to do, it’s always better to know how much fuel is in the tank. The utility company often provides intertie-capable meters at no cost.

Main DC Disconnect (aka: Battery / Inverter Disconnect): In battery-based systems, a disconnect between the batteries and inverter is required. This disconnect is typically a large, DC-rated breaker mounted in a sheet metal enclosure. This breaker allows the inverter to be quickly disconnected from the batteries for service, and protects the inverter-to-battery wiring against electrical fires.

A Sunny Boy grid-tie inverter

Inverter (aka: DC-to-AC Converter or Power Conditioning Unit): Inverters transform the electricity produced by your wind generator into the AC electricity commonly used in most homes for powering lights and appliances. Grid-tied inverters synchronize the electricity they produce with the grid’s “utility grade” AC electricity, allowing the system to feed wind electricity to the utility grid.

Grid-tie inverters are either designed to operate with or without batteries. Battery-based inverters for off-grid or grid-tie systems often include a battery charger, which is capable of charging a battery bank from either the grid or a backup generator during cloudy weather. Some inverters include: Sunny Boy, Siemens, etc.

AC Breaker Panel (aka: Mains Panel, Breaker Box, or Fuse Box): The AC breaker panel, or mains panel, is the point at which all of a home’s electrical wiring meets with the “provider” of the electricity, whether that’s the grid or a wind-electric system. This wall-mounted panel or box is usually installed in a utility room, basement, garage, or on the exterior of the building. It contains a number of labeled circuit breakers that route electricity to the various rooms throughout a house. These breakers allow electricity to be disconnected for servicing, and also protect the building’s wiring against electrical fires.

Just like the electrical circuits in your home or office, an inverter’s electrical output needs to be routed through an AC circuit breaker. This breaker is usually mounted inside the building’s mains panel. It enables the inverter to be disconnected from either the grid or from electrical loads if servicing is necessary. The breaker also safeguards the circuit’s electrical wiring.

Backup Generator (aka: Emergency Backup, Gas-guzzler, “The Noise”): Off-grid wind-electric systems can be sized to provide electricity during calm periods when the wind doesn’t blow. But sizing a system to cover a worst-case scenario, like several calm weeks during the summer, can result in a very large, expensive system that will rarely get used to its capacity and will run a huge surplus in windy times. To spare your pocketbook, go with at least two sources of energy. Wind–PV hybrid systems are often an excellent fit with local renewable resources. But a backup, fuel-powered generator still may be necessary.

Engine-generators can be fueled with biodiesel, petroleum diesel, gasoline, or propane, depending on the design. Most generators produce AC electricity that a battery charger (either standalone or incorporated into an inverter) converts to DC energy, which is stored in batteries. Like most internal combustion engines, generators tend to be loud and produce exhaust that smells bad and is not good for the environment, but a well-designed renewable energy system should require running them 50 to 200 hours a year or less.

INSTALLATION

Installation of a wind turbine involves assembly and construction as well as electrical integration. A typical project includes:

Excavation

Concrete forms and footings

Electrical conduit installation

Mechanical assembly of wind turbine and tower

Placement of turbine, typically hoisted into place via a crane or any towing car

Building codes & zoning regulations: Local building codes may dictate using a heavier tower and larger foundation than expected. Zoning regulations may limit you to a specific tower type or tower height, or impose other requirements that will affect project economics. We’ll be creating a video discussing our experience with our county and these issues.

VIDEO COMING OF: UNDERSTANDING BUILDING CODES FOR WIND SYSTEM INSTALLATION – THIS TUTORIAL WILL TALK ABOUT BUILDING CODES, ZONING, AND WHAT TO BE AWARE OF WHEN WORKING WITH YOUR LOCAL BUILDING AUTHORITIES

Engineering: Turbines exert many complex forces on the tower and its foundation. The larger the turbine, the more robust the tower and foundation need to be. The turbine, tower, and foundation function as a system, and need to be engineered to work together. Most turbine manufacturers offer or recommend an appropriate tower for their turbines. We’ll share our engineered plans once complete. Here’s a video about wind turbine engineering too:

Site conditions: Soil type affects foundation design and may limit tower options. Soft soil or bedrock tends to require more robust foundations than “average” soil. Uneven terrain can be a determining factor as well. Once our wind system is built, we’ll be creating and adding here a video discussing our experience with our soil and how it affected our construction.

VIDEO COMING OF: SITE CONDITION CONSIDERATIONS FOR WIND SYSTEM INSTALLATION – THIS VIDEO WILL DISCUSS SOIL TYPES AND HOW OUR CONSTRUCTION ADDRESSED THE DETAILS OF OURS

Site access: Site access is frequently overlooked. Can the site accommodate very heavy-wheeled equipment, such as a crane and concrete delivery truck? If it can’t, then your tower options are quite limited. Once installed, we’ll add here a video discussing everything we learned and did wrong or right in considering site access too.

VIDEO COMING OF: SITE ACCESS, THINGS TO CONSIDER – THIS VIDEO WILL DISCUSS ALL THE CONSIDERATIONS WE TOOK INTO ACCOUNT FOR OUR INSTALLATION AND ANY WE MISSED AND THE CONSEQUENCES OF MISSING THEM

Tower Erection: There is a startup called Nabralift which promises to decrease the cost of tower erection by 30% by using their patented technology of stacking the tower from the ground up. This could replace the crane and other equipment needed for normal tower erection. This makes a huge difference because it also eliminates the process of the turbine being mounted on the tower after it is erected. You can see some support videos regarding installation for help in the reference section.

Here’s an example by the team at Old House on how to install a home wind turbine :

The steps involved in the example video above are as follows:

Dig a hole 9 feet in diameter and fill it with concrete for the footing.

Dig a trench from the footing to the inverter location and run underground wire in the trench.

Assemble a 60-foot monopole.

Pull electrical wire through the 60-foot wind tower and through the conduit of nacelle.

Hand-tighten the threaded connection of the nacelle to the pole.

Lock down the threaded connection of the nacelle to the pole with a chain wrench.

Make the wire connections in the nacelle.

Secure the tail vane with two bolts using a wrench.

Mount the blades on the shaft of the nacelle.

Tighten up the blades with a reverse threaded nut using a wrench.

Place covers on the center of the blades and the sides of the nacelle.

Connect guide wire to the wind tower and run it to the winch.

Using a winch, pull in the wire and guide the tower into the upright position.

Secure the tower to the base using bolts, nuts, and the wrench.

MAINTENANCE AND CARE CONSIDERATIONS

If you want a simple, reliable, maintenance-free renewable electricity system, buy solar-electric modules. Wind-electric systems are not for the faint-of-heart, and will probably never be a simple “appliance” that you can install and forget about. These are spinning machines in a very harsh environment. You don’t expect your car to operate without maintenance, and you choose and drive it carefully to avoid accidents. The same is true of wind-electric systems. Wind-electric systems are very satisfying when they work, but very disappointing (and visible) when they don’t.

If it’s human-made and has moving parts, it needs maintenance. It doesn’t matter if it’s a spinning engine, a spinning wheel, or a spinning wind generator. You can’t run a car for years, or even months, without maintenance and expect it to last long. And it’s no different with a wind generator. Once a year is a minimum for inspection and maintenance, and twice a year is usually better, especially if you have a good wind resource or experience frequent high winds or turbulence. That said, with proper installation and maintenance, a small wind electric system should last 20 years or even longer.

Something else our research made very clear was to not buy cheap equipment and do buy a tall tower. Buying the best turbine for your site, regardless of price, and putting it on the tallest tower possible will provide more power and less headaches in the long term. Almost all of the disappointment reported from wind energy users is related to buying lightweight equipment for heavy-duty sites, or installing equipment on towers that are not high enough above surrounding obstructions.

TURBINE MAINTENANCE AND CARE

Turbine maintenance and care includes everything to do with your machinery. Annual maintenance should include:

Checking and tightening bolts and electrical connections as necessary

Checking machines for corrosion and the guy wires for proper tension

Checking for and replacing any worn leading edge tape on the turbine blades, if needed

Replacing the turbine blades and/or bearings after 10 years, if needed

If you do not have the expertise to maintain the system, your installer may provide a service and maintenance program. Once we’ve installed our own system, we will also add here videos for each of the above bullets to help with understanding the specifics of each areas of maintenance.

The good news is, most modern wind generators do not have parts that need to be routinely replaced, like the brushes or bearings of older machines. So routine maintenance is primarily focused on inspection of the whole machine, cleaning, and tightening hardware. The spinning turbine and wind forces acting on a tower can cause vibration, which can loosen or damage hard­ware, turnbuckles, and other tower and turbine components. These are the types of things to watch for during an inspection.

Also, before starting your inspection, it is a good idea to prepare all the climbing gear, tools, supplies, and spare parts you may need for the job. Have a good checklist prepared and use it. Another good idea is using a digital camera to record any problems found and having all the equipment manuals available.

VIDEO COMING OF: WIND TURBINE MAINTENANCE AND CARE PROCESS – THIS VIDEO WILL DISCUSS ALL ASPECTS OF ONE COMMUNITY’S ONGOING MAINTENANCE AND CARE PROCESS FOR THE WIND TURBINES, OUR CHECKLIST, PROCESS FOR REPAIRS WHEN NEEDED, AND TUTORIALS FOR ALL THE MAINTENANCE PROCESSES

ELECTRICAL COMPONENT MAINTENANCE AND CARE

In addition to maintenance and care of the hardware in the air, there is also the maintenance and care of all the electrical components on the ground. Finding any problems on the ground and prior to climbing and working on the turbine itself is a good idea. The following areas to check are associated with any kind of electrical system, which could be solar or wind.

Turbine to Inverter/Controller Wire Run

Look for signs of damage on all conduit, wire runs, junction boxes, and conduit fittings, such as water intrusion, condensation, chew marks from critters, cracks, frost-heaving, and so on. Long conduit runs that were improperly installed can store several gallons of water, so be aware when opening junction boxes.

Check wire terminals on all components (disconnects, junction boxes, inverter, controller) for proper tightness and signs of arcing or other degradation.

Test all fuses and circuit breakers for electrical deterior­ation using the continuity tester on a multimeter and look for physical deterioration. Cartridge fuses can deteriorate over time, especially in outdoor installations.

Use a multimeter to check all surge arresters. (surge arresters are things like lightning rods)

Use a megohmmeter on wire runs to check for ground faults. Skinned or cracked wire insulation in underground conduit is one of the most common causes of ground faults. At the very least, system performance will suffer. Some older inverters can be damaged by ground faults. Worse yet, if the equipment grounding system is compromised as well, a shock hazard can result.

While the turbine is operating, check for balanced three-phase output (when applicable, it could be single phase too). Allow for the fact that there will be variations in the wind speed and thus the voltage while you are moving the meter probes—you’re looking for variations of 10% or more between phases. Test two or three times to rule out variations caused by changing wind speed.

Perform other turbine-specific electrical tests per the manufacturer’s recommendations. A good owner’s manual will include testing protocols for the turbine electronics.

As with above, once we’ve installed our own system, we will add here videos for each of the above bullets to help with understanding the specifics of each areas of maintenance.

VIDEO COMING OF: WIND-SYSTEM ELECTRICAL MAINTENANCE AND CARE – THIS VIDEO WILL DISCUSS ALL ASPECTS OF OUR MAINTENANCE AND CARE PROCESS FOR THE WIND SYSTEM ELECTRICAL FROM THE WIND TURBINE TO THE BREAKER BOX FOR THE BUILDING

INDUSTRY OUTLOOK

Wind energy is arguably the most underappreciated and underutilized source of energy. This is mostly due to three reasons:

The initial cost is high and the setup and maintenance are complex for individual use. Maintenance on a large scale (such as farms) also requires skilled workers

It is not available everywhere (like sunlight) and this poses some limitation. Also, it is an intermittent source of energy due to unpredictable and uncontrollable winds

Many believe that wind mills cause too much noise and/or bird death that disturbs the avian ecology of the area

All these reasons have made wind less popular and more costly. The price of wind continues to fall though, and subsidies and incentives exist that further lower prices and make these systems more attractive. Intermittencies are being combated with better and better battery technologies, and bird deaths can be avoided by proper siting and ultrasonic deflectors. Systems are also becoming quieter.

Looking at wind power systems over the next 10 years, the popularity and broad-scale implementation will predictably continue to increase for these additional reasons:

Huge incentives and subsidies that some countries like China and India have started to give to those who use wind power.

Extensive amounts of research (e.g. Tesla Powerwall) is going into making batteries cheaper and more powerful .

Research that some companies are doing regarding huge offshore turbines along the coastlines of their countries. Offshore is certainly the future of large wind farms. Some oil companies are planning to make use of their dried up offshore drilling platforms as the site of windmills.

Some companies are working on airborne wind turbines as well. An airborne wind turbine is a design concept for a wind turbine with a rotor supported in the air without a tower. These systems benefiting from more mechanical and aerodynamic options, the higher velocity and persistence of wind at high altitudes, and avoiding the expense of tower construction. An electrical generator may be on the ground or airborne too. Challenges include safely suspending and maintaining turbines hundreds of meters off the ground in high winds and storms, transferring the harvested and/or generated power back to earth, and interference with aviation. Many companies have already come out with their own designs though and are in their testing phases. These designs are broadly classified as: Systems supported by balloon buoyancy, Kites (lifting aerofoils) and tethered auto gyros. Some of the companies developing these are Makani Power (Google), Windlift, and Altaeros BAT.

An Indian start up by the name Avant Garde innovations is also making wind turbines to power an average Indian home with a wind system for under $1,000.

In short, the future of wind power is bright with governments across the world are becoming more and more aware of the economic and environmental benefits of sustainable energy. Depending on the country you live in and your wind availability, most people have access to viable and relatively affordable wind power systems right now, and these systems can be expected to get cheaper, easier to install, and more widespread from this point forward.

Choosing a Wind Turbine and Tower PDF: In this article you can find the chart to calculate your energy needs. This link talks about choosing your tower and guy wires too. Also, has a schematic for a hybrid wind-solar system.

SUMMARY

One Community will continue to develop this page until every aspect of a working and replicable system is described with written, video, and downloadable tutorials. We will do this as part of constructing the Duplicable City Center and the first of the 7 villages and then continue to update it as we expand and build the other 6 villages. In the meantime and if you are building a system before we do, here’s a summary of the information you’ll need and the decisions you have to make:

The amount of wind at your site

The zoning requirements and covenants in your area

The economics, payback, and incentives of installing a wind system at your site

Purchase and install a wind turbine sized to the needs of your household

One Community will continue to develop this page until every aspect of a working and replicable system is described with written, video, and downloadable tutorials. We will do this as part of constructing the Duplicable City Center and the first of the 7 villages and then continue to update it as we expand and build the other 6 villages. In the meantime and if you are building a system before we do, here’s a summary of the information you’ll need and the decisions you have to make:

The amount of wind at your site

The zoning requirements and covenants in your area

The economics, payback, and incentives of installing a wind system at your site

Regarding installation and maintenance: (Only if you are doing it yourself)

Pouring a proper cement foundation.

A way of erecting the tower safely

Knowing the difference between alternating current (AC) and direct current (DC) wiring

Knowing enough about electricity to safely wire the turbine

Knowing how to safely handle and install batteries

There are pros and cons and good times and bad times for everything. But one thing is for sure, the future of wind energy is bright.

Birds and bats are occasionally killed in collisions with wind turbines. Like any form of development, wind projects can also negatively impact wildlife by altering habitat. Over the past two decades, the impact of wind development on birds has been greatly reduced by improvements in turbine design and particularly through improved project and turbine siting, also use of ultrasonic deflectors. Even if all existing systems were older systems though, global bird deaths and environmental damage from wind systems would still be significantly lower than that caused by non-renewable energy sources like oil and coal.

Q: Should I connect to the grid?

Small wind energy turbines may be installed as stand-alone systems, or they may be connected to the utility grid. Connecting to the grid requires the approval of the utility. Technical and insurance requirements for interconnection vary, as do metering arrangements. Connecting your system to the utility grid allows you to sell excess power that you generate to the utility, as well as to buy electricity from the utility when your needs exceed your wind-powered generation. Interconnected systems do not require batteries. If your utility offers a net metering or billing arrangement, you can even sell your excess power at the same price you pay for electricity you purchase, thereby increasing the value of your wind energy system investment and shortening your payback period.

Q: What is “capacity factor”?

A conventional utility power plant uses fuel, so it will normally run much of the time unless it is idled by equipment problems or for maintenance. A capacity factor of 40% to 80% is typical for conventional plants.

A wind plant is “fueled” by the wind, which blows steadily at times and not at all at other times. Most modern utility-scale wind turbines operate with a capacity factor of 25% to 40%, although they may achieve higher capacity factors during windy weeks or months. It is possible to achieve much higher capacity factors by combining wind with a storage technology such as pumped hydro or compressed-air energy storage (CAES).

Q: What are wind turbines made of?

Wind turbine towers are generally made of steel. The blades are made of glass-fibre reinforced polyester or wood-epoxy. The finish in most models is matt, to reduce reflected light.

Q: How much of the time do wind turbines produce electricity?

A modern wind turbine produces electricity 70-85% of the time, generating different outputs at different times depending on wind speed.

Q: Are wind turbines noisy?

The majority of modern small wind turbines have been designed to be very quiet. They achieve this through technology like direct-drive systems that avoid gearbox noise and increase efficiency. Nowadays, the wind itself makes more noise than a wind turbine and it is unlikely that any noise will be heard from small wind turbines at more than 50 meters.

Q: Are there any problems with low frequency noise?

Small wind turbines do not cause low frequency noise issues.

Q: Do wind turbines affect radar systems or TV reception?

Small wind turbines are unlikely to have any detrimental effects on aviation and associated radar or navigation systems. In general, turbines with small diameters are unlikely to have effects on television and radio reception. If this occurs it is likely to be highly localised and technically easy to overcome. It is also unlikely that building-mounted wind turbines will affect either mobile phone reception or fixed radio or microwave communications links.

Q: Do turbines affect ground-based animals?

Turbines do not adversely affect ground-based animals at all. Installations exist on farms, nature centers, and equestrian centers with no problems for the animals.

Q: What about lightning strikes?

Lightning strikes can cause damage to any structure raised from the ground. However, lightning protection is a well-known practice and can be applied to wind turbines the same as for other equipment.

Q: How long will a turbine take to pay back its installation costs?

Paybacks will depend on several factors. The main ones are your wind resource and size of turbine, what you pay/get paid for your electricity, and whether you get any sort of grants for the project. You should also factor in maintenance costs and long-term price increases (above inflation) for electricity.

Q: What is the life of a turbine?

Freestanding turbines typically have a design life of 20-25 years.

Q: How far away can I mount the turbine from a building?

Turbines can be mounted as close as 20m or as far away as 500m depending on the turbine type and the cable used to bring the electricity back to the building. The latter point is important as the further away the turbine is, the bigger the cable required to minimize transmission losses and this adds to cost.

Q: How much space do I need to erect a turbine?

Each turbine and tilt-up tower combination requires its own “footprint” on the ground. As a rough guide, taking the tower height and multiplying it by 2.5 will give you an approximate horizontal length required on the ground. The width would be the rotor diameter plus 2 meters to allow enough space for raising and lowering. Guyed towers require more space.

Q: Will the turbine affect my own or my neighbor’s property price?

Chances are that it will add value to your property. There is no evidence of wind turbines, large or small, affecting property prices adversely in the long term.

Q: Do I need three-phase electricity supply to host a turbine?

To extract full value from a turbine rated at 5 kW or over, it is preferable (but not essential) to have a three-phase electricity supply. Below 5 kW, it is not necessary and the power generated can be handled comfortably by a single phase connection.

Q: Can a turbine be re-sited?

Yes, provided the new site is suitable. Costs will be incurred to dismantle the turbine, transport it to the new site and re-install it. An estimate of these costs needs to be determined by a survey of the old and new sites.

Q: Why are small wind turbines better than diesel generators or extension of utility lines in developing countries?

Small wind turbines are better because they are more sustainable and offer a number of other socioeconomic benefits. Wind systems come in smaller sizes than diesel generators and have a shorter lead time than extending the utility lines (“grid”). For grid extension distances as short as one kilometer, a wind system can be a lower cost alternative for small loads. While wind turbines cost more initially than diesels, they are often much better from the user’s point of view because of typical foreign aid practices. Donor agencies, for example, typically supply diesels at no cost, but leave operational costs (fuel, maintenance and replacement) to be supplied by the local people. These expenses (in particular, fuel and parts) require hard currency. This usually leads to limited utilization and a shortened diesel lifetime due to inadequate maintenance. Many countries must also import their fossil fuels, further magnifying the burden imposed by diesels. Environmental costs are also a factor.

Q: Aren’t wind turbines too “high-tech” for rural people?

The high technology of a wind turbine is in just a few manufactured components such as the blades. A wind turbine can actually be much simpler than a diesel engine, and also require substantially less attention and maintenance. Some types of small turbines can operate for extended periods, five years or more, without any attention. With training and spare parts, local users can support the wind turbine equipment they use.

Q: What is “net metering” (“net billing”) and how does it work?

Net metering or net billing is a term applied to laws and programs under which a utility allows the meter of a customer with a residential power system (such as a small wind turbine) to turn backward, thereby in effect allowing the customer to deliver any excess electricity produced to the utility on a one-for-one credit basis against any electricity the utility supplies the customer.

Example: During a one-month period, John Doe’s wind turbine generates 300 kilowatt-hours (kWh) of electricity. Most of the electricity is generated at a time when equipment in John’s household (refrigerator, lights, etc.) is drawing electricity and is used on site. However, some is generated at night when most equipment is turned off. At the end of the month, the turbine has generated 100 kWh in excess of John’s instantaneous needs and has transmitted this excess to the utility system. The utility has also supplied John with a total of 500 kWh for his use at times when the wind turbine has not been generating or has been insufficient for his needs. Since the meter ran backward while 100 kWh was being transmitted to the utility, the utility will only bill John for 400 kWh, rather than 500 kWh.

Net metering can dramatically improve the economics of a residential wind turbine by allowing the turbine’s owner to use their excess electricity to offset utility-supplied power at the full retail rate, rather than having to sell the power to the utility at the price the utility pays for the wholesale electricity it buys or generates itself. Many utilities have argued against net metering laws, saying that they are being required, in effect, to buy power from wind turbine owners at full retail rates, and are therefore being deprived of a profit on part of their electricity sales. However, wind energy advocates have successfully argued that what is going on is a power swap, and that it is standard practice in the utility industry for utilities to trade power among themselves without accounting for differences in the cost of generating the various kilowatt-hours involved.

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